MissingPluginException when trying to use

[ShehabSN]

I followed the docs and i tried to use the example code for getting the distancebetween two geo points below:

double distanceInMeters = await Geolocator().distanceBetween(52.2165157, 6.9437819, 52.3546274, 4.8285838);
          print(distanceInMeters);

This didn't work however and i got an exception:

Unhandled Exception: MissingPluginException(No implementation found for method distanceBetween on channel flutter.baseflow.com/geolocator/methods)

Any ideas why this is happening? I ran packages get,upgrade, even flutter upgrade and still the same issue. Is this method deprecated or removed?

[mvanbeusekom]

@ShehabSN, I have been looking in to this issue but having a hard time reproducing it. Using the example app (part of the Geolocator plugin). Could you maybe supply a bit more information? Questions right out of the box are:

• Which version of the plugin are you using (maybe you are using an outdated version and you should update, we tested with 5.1.1 and 5.1.2)?
• Do you get this error on both (Android and iOS) platforms (I tested both platforms and both worked)?
• Which version of Flutter do you use?

[mvanbeusekom]

Closing this issue because of lack of activity. Feel free to re-open it and supply the requested additional information when the issue resurfaces.

[dougsibley]

Hi - I'm having this issue as well in trying to run unit testing. Perhaps it is because I'm calculating distances before creating a GeoLocator object/stream and starting to get any location. That said, I'm not clear why the distanceBetween function is a Future function; I would have thought it would make sense to be a static class method.

Code to reproduce this is below.

car_trip.dart:

import 'package:geolocator/geolocator.dart';

class CarTrip {
  double tripDistance = 0; // Distance in meters
  var _geoLocator = Geolocator();

  List<Position> _tripWaypoints; // List of positions returned by GPS in a trip

  Future<void> addWaypoint(Position newWaypoint) async {
    if (_tripWaypoints == null) {
      _tripWaypoints = [newWaypoint];
    } else {
      Position priorWaypoint = _tripWaypoints.last;
      tripDistance += await _geoLocator.distanceBetween(priorWaypoint.latitude,
          priorWaypoint.longitude, newWaypoint.latitude, newWaypoint.longitude);
      _tripWaypoints.add(newWaypoint);
    }
    
    print("NewWaypoint: ${newWaypoint.latitude}, ${newWaypoint.longitude}");

    // TODO: Add trip time. 

  } // addWaypoint
} // class CarTrip

car_trip_test.dart:

import 'package:carcost/cartrip.dart';
import 'package:geolocator/geolocator.dart';
import 'package:flutter_test/flutter_test.dart';

main() {
  TestWidgetsFlutterBinding.ensureInitialized();
  test('Distance between waypoints should be non-zero.', () async {
    // Unit test
    Position pos1 = Position(latitude: 33, longitude: 33);
    Position pos2 = Position(latitude: 34, longitude: 34);

    CarTrip testCarTrip = CarTrip();
    await testCarTrip.addWaypoint(pos1);
    await testCarTrip.addWaypoint(pos2);
    print("Test distance is ${testCarTrip.tripDistance} ");
    expect(testCarTrip.tripDistance, 145000);
  });
}

[dan-gandolfo]

Hi,

I have the same issue when I call Geolocator.isLocationServiceEnabled() in a background isolate function.

Have you a workaround to fix it?

Doctor summary (to see all details, run flutter doctor -v): [✓] Flutter (Channel stable, 2.10.5, on macOS 12.3.1 21E258 darwin-arm, locale fr-FR) [✓] Android toolchain - develop for Android devices (Android SDK version 32.1.0-rc1) [✓] Xcode - develop for iOS and macOS (Xcode 13.4.1) [✓] Chrome - develop for the web [✓] Android Studio (version 2021.1) [✓] VS Code (version 1.67.2) [✓] Connected device (4 available) [✓] HTTP Host Availability

geolocator: ^8.2.1

[mvanbeusekom]

Hi @dangabdolfo,

The solution to this is described in this comment.